Form tie



Aug. 21, 1934.

.-c. SCHENK FORM TIE Filed July 11 1933 INVENTOR Tamid 645117116 4,

ATTORNEY Patented Aug. 21, 1934 FORM' TIE Tamis C. Schenk, New York, N. Y., assignor to Richmond Screw Anchor (30., Inc., Brooklyn, N. Y a corporation of New York Application July 11, 1933, Serial No. 679,879

1Claim.

This invention relates to an improvement in form ties usually used for holding together forms used in concrete work. One of the conventional types of form ties consists of a device composed 5 of several spaced parallel rods between which are located several helixes or spirals which receive the lag screws that pass through the wooden forms. One of thedefects encountered in this type of 'form tie is the tendency of the screws to loosen due to vibration and other causes, so that these screws have to be readiusted after the forms are in position orielse there is a likelihood of the forms becoming disaligned.

The object of this invention is to provide a form tie of this character having means for so engaging the threaded portions of the lag screws that an 'unthreadingmovement of the screws is prevented and consequently the possibility of the forms becoming disaligned will be avoided. More specifically, the invention contemplates a form tie composed of several parallel rods between which is secured several helixes into which the screws enter, these helixes being provid'ed with bent or distorted ends that engage the lag screw threads and frictionally resist the turning movement or the screws.

In the accompanying drawing, Fig. 1 is a side elevation of the improved form tie, the form boards being shown in section; Fig. 2 is a sectional view on the line 2-2 of Fig. 1, looking in the directionof the arrows; and Fig. 3 is a sectional view on the line 3-3 of Fig. 1, looking in the direction of the arrows.

At 5 'is shown the form boards constituting the form between which the concrete is placed. The vertical re-enforces for the form are shown at 6, and the longitudinal braces for the form are shown at '7. The form tie consistsof a pair of parallel rods 8, between which are shown the 40 helixes 9. .These helixes are in .the form of a spiral rod and are welded to the two rods 8 near their ends. The lag screws are shown at 10, said screws passing through the boards 5 and re-enforces 6 and '7, the threaded portion 11 on each of the screws engaging with one of the helixes.

Each helix has its inner end 12 distorted or bent away fromthe body of the helix so that it is partially disaligned with the spaces between the threads of the lag screws. When the screw is threaded in position within the helix the bent end 12 of the helix is sprung slightly as indicated by the relation of the dotted and full lines in Fig. 2, and it exerts frictional pressure against the threads of the screw so that it resists any tuming tendency of the screw. The frictional pressure of the bent end 12 is just suflicient to prevent any inadvertent turning of the screw by reason of the vibration or strain. yet insufficient to prevent proper rotation of the screw by the use of a suitable tool. The bent portion 12 of 7 each of the helixes acts as a locking means for the screws and once the forms are properly in position, they will not become disaligned and further tightening of the screws or trueing of the forms is avoided.

What I claim'is:

A,form tie having several parallel rods, a helix for the reception of a lag screw located between TAMIS c. SCHENK. 

